Find the value of angle d.

The triangle in option d) is isosceles because it has two sides with the same length as indicated by the ticks on the sides. In an isosceles triangle, the angles opposite the equal sides are also equal. Therefore, angle d is equal to the angle opposite the other equal side. Let's call this angle x. The sum of the angles in any triangle is 180 degrees. We can write the equation: $$110^{\circ} + x + d = 180^{\circ}$$ Since $$x = d$$, we can substitute d for x: $$110^{\circ} + d + d = 180^{\circ}$$ $$110^{\circ} + 2d = 180^{\circ}$$ Now, let's solve for d: $$2d = 180^{\circ} - 110^{\circ}$$ $$2d = 70^{\circ}$$ $$d = \frac{70^{\circ}}{2}$$ $$d = 35^{\circ}$$ Answer: 35 degrees